It is often desirable to incorporate an adjustment feature in a floor-engaging support or pedestal for a table, work surface and the like. This feature allows the height of the tabletop to be adjusted relative to the floor and to thereby comfortably accommodate workers of varying stature.
Adjustable features have been employed in prior art supports for various extensible articles. For example, the Recker Pat. No. 1,970,624, issued Aug, 21, 1934, discloses an adjustable support for lighting fixtures, tables and the like comprising a lower tube and an upper rod telescopically positioned within the lower tube. The rod is secured within the tube at the desired position of adjustment relative to the tube through the rotation of a clamping nut which threadably engages the tube and tightens, when screwed firmly onto the tube, a split flange around the periphery of the rod. In addition, the Rich Pat. No. 275,413, issued Apr. 10, 1883, discloses a piano stool having a base, seat and adjustable support positioned therebetween. The support includes a threaded lower rod secured to the base and an upper tube securely attached at its top portion to the underside of the table and threadably engaging at its bottom portion the threads of the lower rod. The stool is adjusted to the height desired by simply rotating the upper tube by exerting rotational force on the seat. Finally, the Perry Pat. No. 1,451,999, issued Apr. 17, 1923, discloses a furniture leveling device secured to the leg of a piece of furniture. The device comprises an interiorly threaded socket rigidly housed within the leg and a leveling member threadably engaging the socket, wherein the latter is set in the adjusted position relative to the former by rotating the leveling member in the appropriate direction. To secure the leveling member in adjusted position, a spring, comprising a flat steel strip, is rigidly secured at one end to the leveling member and adapated to enter at its other end any one of a number of notches in the socket so as to normally hold the leveling member stationary and resist rotation thereof while permitting rotation when sufficient force is supplied thereto to overcome such resistance.